Methane levels in shallow subtropical lake sediments: Dependence on the trophic status of the lake and allochthonous input

Abstract

a b s t r a c tThe vertical sediment profiles (10 cm) of the margins of three shallow subtropical lakes (Rio Grande, Brazil) with different trophic states and surrounding areas were evaluated to identify the effects of the allochthonous input on the methane concentration in the sediment. Sediment cores were collected to quantify the organic matter content (OM) and total carbon (TC), total nitrogen (TN), total phosphorous (TP) and methane (CH 4 ) concentrations.The three lakes were distinguished according to the trophic status and classified as oligotrophic, dystrophic and eutrophic. The natural characteristics of the dystrophic and eutrophic lakes have been changed due to the allochthonous input of leaves and twigs (Eucalyptus sp.) and the excreta of birds, respectively. In the eutrophic lake, the allochthonous input contributed to high autochthonous production. The highest values of OM, TC, TN and TP were found in the superficial sediments of the dystrophic and eutrophic lakes. The accumulation of allochthonous organic matter in the littoral zone promoted changes in the vertical sediment profiles and contributed to increases in the CH 4 concentrations in the sediment.

Fluxes of greenhouse gases at two different aquaculture ponds in the coastal zone of southeastern China

“…The CH 4 flux showed a significant positive correlation with trophic status and Chlorophyll-a, and a significant positive correlation was also found between trophic status and Chlorophyll-a concentrations (Table 1), which further support the above hypothesis. Similar study results have been found in other global aquatic ecosystems (Flury et al, 2010;Schrier-Uijl et al, 2011;Furlanetto et al, 2012).…”

Gases invernadero en aguas con bajo oxígeno en el reservorio eutrófico de Prado (Colombia)

“…Actualmente se estima que entre 6 y 16 % de las emisiones naturales de CH 4 provienen de los lagos y ríos; en ese sentido, los datos aquí registrados concuerdan con lo reportado por Palma-Silva, et al, (2013) en otros lagos en los cuales se registró claramente el proceso de metanogénesis en los sedimentos (con producciones de hasta 1.727 µmol/g) y en la columna de agua (hasta 19,9 µmol/l), así como en la columna de agua anóxica (Borrel, et al, 2011, Furlanetto, et al, 2012, e incluso en la columna de agua oxigenada de algunos lagos (Grossart, et al, 2011). En general, los valores de saturación superficial encontrados en Prado (420-1.200 %) estaban en el mismo rango reportado para otras hidroeléctricas, con valores de hasta 600 µM (Sturm, et al, 2013, Soumis, et al, 2004, aunque por debajo de lo reportado en la superficie de lagos someros (entre 2.000 y 8.000 %) por Wang, et al, (2010).…”

Spatial variations of methane emission in a large shallow eutrophic lake in subtropical climate

“…These two zones receive two thirds of the rivers runoff into the lake [Zhai et al, 2010]. The lack of temperature influence in these zones suggests that high nutrient inputs [Furlanetto et al, 2012;Rasilo et al, 2015] and high sediment loads [Natchimuthu et al, 2015] may have confounded the direct effect of temperature on the CH 4 flux. Natchimuthu et al [2015] observed higher CH 4 concentration in lake zones that receive stream water than their whole-lake mean concentration and proposed that enhanced CH 4 production in sediments in these zones is a factor contributing to this difference.…”